John Lewis NN-GT578SBJQ OEM 27L JLFSMWG002 User Manual

HAD0901002C2
Microwave Oven
NN-GT578SBJQ
OEM 27L JLFSMWG002
NN-A764WBEPG
NN-A764WBWPG
! WARNING
This service information is designed for experienced repair technicians only and is not designed for use by the
general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers
in attempting to service a product. Products powered by electricity must be serviced or repaired only by expe-
rienced proffesional technicians. Any attempt to service or repair the product or products dealt with this service
information by anyone else could result in serious injury or death.
There are special components used in this equipment which are important for safety. These parts are marked
by (!) in the schematic diagrams, circuit board diagrams, exploded views and replacement parts lists. It is
essential that these critical parts are replaced with parts specified by the manufacturer, preventing shock, fire
or other hazards. Do not modify the original design without permission from the manufacturer.
IMPORTANT SAFETY NOTICE
© Panasonic Home Appliance Division. 2008
Unauthorized copying and distribution is a
violation of law.

John Lewis NN-GT578SBJQ OEM 27L JLFSMWG002 Specifications

General

Capacity	27L
Power Output	900W
Cavity Material	Stainless Steel
Model Number	NN-GT578SBJQ
OEM Number	JLFSMWG002

Summary

Control Panel

Inverter Warnings

Inverter Safety Precautions

Highlights dangers and warnings associated with the high-voltage inverter circuit.

Cautions for Troubleshooting

8.1 Grounding Checks

8.2 Inverter Power Supply Warnings

Specific dangers and high voltage warnings for the inverter power supply.

Parts Replacement Procedure

9.1 Magnetron Replacement

9.2 Inverter Circuit Replacement

9.3 Digital Programmer Circuit and Keyboard

Component Test Procedure

10.1 Latch Switch and Power Relay Interlocks

10.2 Short Switch and Monitor Circuit Test

10.3 Magnetron Testing

10.5 Inverter Power Supply Test

10.6 Inverter Power Supply Unit

Measurements and Adjustments

11.1 Latch Switch Installation and Adjustment

11.2 Microwave Output Measurement

Troubleshooting Guide

12.1 Troubleshooting (no operation)

Identifies causes and corrections for the oven not operating.

12.2 Troubleshooting (fuse blown)

Identifies causes and corrections when the main fuse is blown.

12.3 Troubleshooting (other problems)

Addresses issues like low output, buzzing noise, and turntable problems.

12.4 Troubleshooting Inverter by Input Voltage

Diagnoses inverter shutdown issues based on input voltage and test mode.

12.5 Troubleshooting Inverter by Input Current

Diagnoses inverter shutdown issues by monitoring input current.

12.6 Digital Programmer Circuit Troubleshooting

Guides for diagnosing issues with the digital programmer circuit.

12.7 Checking Semiconductors